Process for the manufacture of 2,4-dicyano-3,5-dimethylaniline

ABSTRACT

Preparation of 2,4-dicyano-3,5-dimethylaniline by heating Beta -methyleneglutaric acid dinitrile or Beta -methylglutaconic acid dinitrile or mixtures of these dinitriles to temperatures above 100*C in the presence of basic catalysts. The resulting aniline is a starting material for the production of valuable azo dyestuffs.

United States Patent Komorowski et al.

[4 1 May 20, 1975 PROCESS FOR THE MANUFACTURE OF 2,4-DICYANO-3,5-DIMETHYLANILINE Inventors: Klaus Komorowski, Cologne; Peter Kurtz, Tegernsee, both of Germany Bayer Aktiengesellschaft, Leverkusen, Germany Filed: May 18, 1973 Appl. No.: 361,507

Assignee:

Foreign Application Priority Data May 6, 1972 Germany 2222381 US. Cl 260/465 E; 260/155; 260/156;

260/163; 260/165; 260/205; 260/999 Int. Cl. C07c 121/78 Field of Search 260/465 E [56] References Cited FOREIGN PATENTS OR APPLICATIONS 958,922 2/l957 Germany Primary E.\'aml'nerLewis Gotts Assistant ExaminerDolph H. Torrence Attorney, Agenl, or FirmPlumley & Tyner 7 Claims, N0 Drawings PROCESS FOR THE MANUFACTURE OF 2,4-DICYANO-3,5-DIMETHYLANILINE It has been found that 2,4-dicyano-3,5- dimethylaniline is obtained in very good yields in a one- The bases are appropriately used in amounts of 0.001 mol per cent to 2 mol per cent, relative to the dinitriles The reaction product (III) according to the invention pot reaction if ,B-methyleneglutaric acid dinitrile or 5 is avaluable intermediate product for the manufacture B-methylglutaconic acid dinitrile or mixtures of these of pesticides and above all of dyestuffs, preferably azo dinitriles optionally in an inert solvent are heated dyestuffs. to temperatures above 100C in the presence of basic For example, in order to manufacture azo d estuffs,

y catalysts. the new aniline derivative (III) is diazotised and cou- The course of the reaction can be illustrated in more pled, in a known manner, with customar cou lin y P 8 detail by the following equation: components of the aniline, pyridone, quinoline, indole CH CN 2 CH =C CH Cl\ l 5 %N CH N Ia Bases 5 3 /CHCN 2 on 2 011 -0 32 2 CH CN II III It must be described as distinctly surprising that the or pyrazolone series. relatively complicated amine (III), which it has not The process according to the invention will be exhitherto been possible to prepare in a conventional plained in more detail with the aid of the examples manner, is obtained in this simple manner. which follow.

Admittedly it is already known from German Patent Specification 958,922 to allow basic catalysts to act on EXAMPLE 1 the dinitriles (l), but the reaction described therein, 5 which is carried out at relatively low temperatures 5 F aclcidmmfle (below 100C) only leads to a dimer of the dinitriles z f g temperamge m 650 g 450 ml (1), which, according to our own more recent analytical 2 135 i enzene n g g f g investigations, should not be allotted the straight-chain a e 8006C 1g i .1 Stan-e h structure proposed in the cited German Patent Specifi- 40 Utes i e.rea er mp1 y t e o] Cation but the Cyclic structure indicated for the inter (218 C), whilst distilling off the acetonitrile liberated. mediate product (In postulated above After reaching the boiling point, the mixture is filtered The cyclisation reaction according to the invention is i g g zfi fiz 'gigg z t gfz i ig 25: 132? :5 preferably carried out without solvents at temperatures f 2 4 3 5 f g l bove 100C especially at 100 to 120C 0 7 lcyano" lmet yanrlne 0 me t n oint a The reactkm can however also be carr'ied out with 205208C crystallise as bI'OWl'llSh crystals. Yield: 76% of theory. (The yield can be improved to approx. 85% eqluany g ';i l T the prtesencebof l t dP f by concentrating the mother liquor). An analytically so Vents y at empera a We Pre pure product of melting point 2102l 1C can be obergblgml 5112513208 iiable highboiling Solvents are di tained from the crystals by high vacuum sublimation. chlorobenzene, trichlorobenzene, dichlorotoluene, dimethylformamide, dimethylacetamide, ethylene glycol, EXAMPLE 2 diethylene glycol, glycol monomethylcther, tetralin, 70 g of B y neglutariC acid dinitrile are disdecalin, dlphenyl ether and others. It is however also Solved in 135 11048 g) of ethylene glycol at possible to employ lower-boiling solvents such as methanol, ethanol, dioxane, diethyl ketone and water but in that case the reaction must be carried out in an autoclave under pressure.

Possible basic catalysts are alkali and alkaline earth hydroxides, alcoholates, phenolates, cyanides and amides, as well as ammonia and organic bases.

As examples there may be mentioned: NaOH, KOH, Ca(OH) NaOCH NaOC l-l NaOC H KOCH KOC. ,H KOC H (tert.), NaOC H (n), NaOC l-l tert). NaOC H KOC H NaNl-1 KCN, Nl-l dimethylamine, diethylamine, trimethylamine, triethylamine, morpholine, piperidine and pyrrolidine.

and 5 g of NaOCH are added slowly. Thereafter the mixture is rapidly heated to C and the acetonitrile thereby liberated is distilled off. The mixture is then poured out, whilst hot, onto 300 ml of ice/H O and the product is filtered off and washed with water until neutral. Yield: 47.6 g 84.3%. Brownish-yellow crystals of melting point 205206C, which are pure enough for further conversion into azo dyestuffs.

Similarly good results are achieved on using the solvents and basic catalysts mentioned in the preceding description. The following experimental results, listed in the form of a table, may be mentioned by way of example.

No Dinitrile in g Base Temperature C Solvent Yield in a 70 g la NaOCH; 5 g 180 Diethyl glycol 135 ml 95 b 20 g lb do. 5 g 210 do. 93 v 20 g lb do. 5 g l7() Glycol I35 ml 87 d 70 g la do. 5 g I50 DMF" 50 ml 89 c 35 g la do. 5 g [50 do. 89

35 g lb f do. Triton B I70 Triehlorobenzene 90 g 70 g la Triethylamine 2 do. )0 h 70 g la NaOCH g 2H) Methanol (in an autoclave) 80 i 70 g la KOC ,H,, g 250 Glycol 95 j 70 g In NaOCH 5 g 170 89 It 70 g lh NaOCH 4 g I40 92 Benzyltrimethylammonium hydroxide "Dimethylt'ormamide l5 EXAMPLE 3 late, phenolate, cyanide or amide; ammonia or organic 5 g of NaOH dissolved in 30 ml of water are added bascto 70 g of fused B-methyleneglutarie acid dinitrile at The Process of Claim 1 m Whlch Sald basic catalyst 90C. The temperature of the reaction mixture rises to NQOH, KOH, l lz NaOCHs, z s 105C. The mixture is stirred for 5 minutes and poured a h KOCHs, z s 4 9( out onto ice/water and the product is filtered off and -l 9 J-M e s, B s" washed until ncutmL NaNH- KCN, NH dlmethylamme, diethylamine, tri- 53 g 98% of 2,4-dicyano-3,S-dimethylaniline of methylafnine, triethylamine, morpholine piperidine or melting point 2()22()4C are obtained. py

w l i 4. The process of claim 2 in which the basic catalyst 1. Process for the preparation of 2,4-dicyano-3,5 is Present in an amount 0-001 to 2 m0] Percent of Said dimethylaniline, comprising the steps of heating [3-me dmltlllethyleneglutaric acid dinitrile or B-methylglutaconic The PTOCCSS OfClalm l m hi h the reaction is Caraeid dinitrile or a mixture thereof in the presence or abfled Out ut l nts at temperatures of 100 to sence of inert solvent to a temperature above 100C in the presence of a basic catalyst under conditions suffi- The Process of Clillm 1 Whlch the b11516 Catalyst cient to form 2,4-dicyano-3,S-dimethylaniline; and re- 15 an dlkllll alcohollltecovering said 2,4-dicyano-3,S-dimethylaniline 7. The process of claim 1 which is continuous and 2, The proce of clai 1 in hi h id b i catalyst free of any step of separation an intermediate comis an alkali metal hydroxide, alcoholate, phenolate, cyp n anidc or amide; an alkaline earth hydroxide, alcoho- 

1. PROCESS FOR THE PREPARATION OF 2,4-DICYANO-3,5DIMETHYLANILINE, COMPRISING THE STEPS OF HEATING BMETHYLENEGLUTARIC ACID DINITRILE OR B-METHYLGLUTACONIC ACID DINITRILE OR A MIXTURE THEREOF IN THE PRESENCE OF ABSENCE OF INERT SOLVENT TO A TEMPERATURE ABOVE 100*C IN THE PRESENCE OF A BASIC CATALYST UNDER CONDITIONS SUFFICIENT TO FORM 2,4DICYANO-3,5-DIMETHYLANILINE; AND RECOVERING SAID 2,4-DICYANO3,5-DIMETHYLANILINE.
 2. The process of claim 1 in which said basic catalyst is an alkali metal hydroxide, alcoholate, phenolate, cyanide or amide; an alkaline earth hydroxide, alcoholate, phenolate, cyanide or amide; ammonia or organic base.
 3. The process of claim 1 in which said basic catalyst is NaOH, KOH, Ca(OH)2, NaOCH3, NaOC2H5, NaOC3H7, KOCH3, KOC2H5, KOC4H9-(tert.), NaOC4H9(n), NaOC4H9(tert.), NaOC6H5, KOC6H5, NaNH2, KCN, NH3, dimethylamine, diethylamine, trimethylamine, triethylamine, morpholine, piperidine or pyrrolidine.
 4. The process of claim 2 in which the basic catalyst is present in an amount 0.001 to 2 mol percent of said dinitrile.
 5. The process of claim 1 in which the reaction is carried out without solvents at temperatures of 100* to 120*C.
 6. The process of claim 1 in which the basic catalyst is an alkali alcoholate.
 7. The process of claim 1 which is continuous and free of any step of separation an intermediate compound. 